Drum-head tightener device



March 19, 1935. R HlERs 1,995,066

DRUM HEAD TIGHTENER DEVICE Filed March 18, 1935 L I I [III I F L27 IENVENTOR.

J ZoE/Ycva K LZ MQQE,

ATTORNEY.

Patented Mar. 19, 1935 UNITED STATES PATENT OFFICE Application March 18,

1 Claim.

This invention relates to improvements in drum manufacture and is directed more particularly to improvements in devices for tightening drum heads or diaphragms.

The principal objects of the invention are directed to the provision of a novel device for tensioning or tightening the heads of drums which is not only simple in form and therefore economical to manufacture but which is eflicient in its operation. Another object of the invention is the provision of a device of the class described which is admirably adapted for the tightening or tensioning function but yet which is so designed that the tension may be slackened without the liability of the tightening device becoming displaced on the drum or moved appreciably from its position.

It is well known that the head or heads of a drum for the proper functioning of the drum must be tensioned or stretched and that the material from which the heads are usually made is inherently susceptible to changes in temperature and climatic conditions wherefore they must be stretched or tensioned in accordance with existing conditions. It is also recognized that it is frequently desired to relieve the head or heads of tension, and this may be accomplished by means of the novel structure of the invention since the tightening device is arranged so that it is not likely to slip around the hoops, but instead is held in place whether or not it is adjusted for the tensioning or tightening function.

Various novel objects and advantages of the invention will be more fully hereinafter referred to in connection with the following description of the preferred form of the invention which for purposes of disclosure is shown in the accompanying drawing wherein:

Fig. 1 is a plan view at a small scale of a drum structure having a plurality of the tensioning devices of the invention associated therewith.

Fig. 2 is an elevational view of a tightening device embodying the novel features of the invention and showing how it is associated with the hoops of a drum.

Fig. 3 is a view similar to Fig. 2 showing a modified form of the invention, and

Fig. 4 is a view similar to Fig. 2 showing another modified form of the invention.

Referring now to the drawing more in detail the invention will be fully described.

Referring more particularly to Fig. 1 there is shown a plan view of a drum. As is well known a drum may have a cylindrical shell and hoops at the upper and lower ends thereof with a head 1933, Serial No. 661,446

0r heads associated with the upper and lower ends. The head is usually made from some more or less elastic or resilient material which may be stretched so that it is sufiiciently taut. The tightening or tensioning is accomplished by moving the hoop or hoops towards one another axially of the shell. When it is desired to relieve the head or heads of tension the hoops are allowed to separate or are relieved of pressure.

In Fig. 2, a shell 4 and upper and lower hoops 2 of the drum are indicated by dot-dash lines. Heads 6 are likewise indicated by dotted lines and are tensioned by means associated with the shell and hoops as the hoops are moved towards one another. of the invention is adapted for use with a drum having hoops at upper and lower ends of a Shell or with a drum having a hoop and head at one end only of a shell.

The tightening device of the invention as shown in Fig. 2 consists of a rod member 10 having a lower hooked end portion 12 for hooking over the lower hoop or the lower end of a shell. A hook member 14 having a hooked end 16 for overlying an upper hoop 2 has a horizontally disposed portion 18 which is apertured so as to be slidable on the rod 10. The upper end 20 of the rod is threaded as shown and has an adjusting member in the form of a nut 22 in screw-threaded engagement therewith.

An actuating member 24 in the form of a coil spring surrounds the rod 10 and is disposed between the nut 22 and the part 18 of the hook 14. The member 24 is preferably made in the form of a spring so as to be more or less yieldable or resilient for a certain purpose.

When it is desired to tighten the head, the nut 22 is turned so as to press on the member 24 which yieldingly forces the member 14 downwardly and the rod 10 upwardly. By turning the nut 22 in the tightening direction the spring 24 is compressed so that its adjacent convolutions are in abutment at which time it in reality becomes a relatively rigid tube like member bearing on the part 18. This rigidity is desirable as it facilitates the application of the desired pressure for moving the hooks 14 and 12 towards one another so that the drum is tightened or tensioned.

When it is desired to slacken the head or relieve it of tension, the nut 22 is turned in an opposite direction. As the nut is turned the spring 24 expands or opens up so that the hooks are subjected to a yielding pressure. Under this yielding pressure which may be varied all as may be desired, the heads are relieved of the tension Y It will be understood that the device while the hooks are held under sufiicient pressure to prevent the device from slipping around the hoops and becoming displaced.

The form of the device shown in Fig. 3 will now be described.

In this form of the invention a rod 30 may have a nut 32 screw threaded on its lower end. A hook member 34 is provided with a hooked end 36 and has a portion 38 slidable on the rod 30.

The lower end 31 of the rod 30 is screw threaded for the nut and a gripping element of some suitable form such as 46 is carried by the upper end of the rod.

An actuating member in the form of a spring 42 is disposed between the member 40 and the part 38 of the upper hook 34. Thiss'pring member 42 as in the former case functions when the drum head or heads are more or less slack" to act with the yielding pressure so that the hooks yieldingly embrace the upper and lower sides of the upper and lower hoops. When the rod is rotated for the tightening function by. means of the member 40 so that the spring is compressed,; the hooks are drawn'towards one another and function as do the hooks previously describedto move the hoop or hoops.

It may be desirable to vary the construction somewhat from that shown as by carrying a hook such as 3-i on the lower end of sucha rod as 10 in Fig. 2. In all cases however it will be desirable to employ the resilient actuating member'such as the spring disposed between the rotatable member and the adjacent hook so that it will function in the manner described.

The form of the invention shown in Fig. 4 will now be described.

In this form of the invention upper and lower hoops 52 have lugs or ears 62 associated therewith. These may be a part of the hoops or separate parts suitably secured to the hoops. A rod 56 extends through the ears 62 and an actuating member 58 such as previously described is asso ciated with one endof the rod 56 as shown. A gripping element 60 may be in screw threaded engagement with the lower end of the rod memher and a head 64 may be provided on the upper end. of the rod. Of course the member 60may be fixed on the rod with the upper end of the rod in threaded engagement with the member 64.

As in the former cases the member 60 is turned to bring about relative movements of the hoops for the purpose desired. A shell and heads are represented at 66 and 68 with which the hoops co-operate, the hoops being circular in form as shown in Fig. 1.

From the foregoing it will be seen that the actuating member in the form of a spring acts to yieldingly draw the hooks towards one another so that the device is yieldingly held against movement relative to the hoops while in the tightening operation, the spring is compressed so that it positively actuates the hooks.

While I have shown the device in association with a drum having a pair of heads it will be obvious that it is adapted to be used in connection with drums having a head at one end thereof. Various changes may be made in the form of the invention without departing from the spirit and scope thereof and what it is desired to claim and secure by Letters Patent of the United States is:

A .device for acting on upper tively movable members of a drum structure to adjust the tension of a drum-head comprising in'combination, a unitary substantially straight and vertically disposed rod member having a relatively rigid grip member integral therewith at its upper end and a screw-threaded portion at its lower end, upper and lower spaced hook memand lower relatated axially of said spring by means or said grip to compress said spring between the grip and upper hook member and yieldingly urge said upper hook member towards said lower hook member.

RALPH H. HIERS. 

